From 99118c1ec445ba7ce0781bc1d5652b14c8a8a7a8 Mon Sep 17 00:00:00 2001 From: Thomas Braun Date: Thu, 8 May 2014 21:43:24 +0200 Subject: [PATCH] Config option to disable side-band-64k for transport Since commit 0c499ea60f the send-pack builtin uses the side-band-64k capability if advertised by the server. Unfortunately this breaks pushing over the dump git protocol if used over a network connection. The detailed reasons for this breakage are (by courtesy of Jeff Preshing, quoted from ttps://groups.google.com/d/msg/msysgit/at8D7J-h7mw/eaLujILGUWoJ): ---------------------------------------------------------------------------- MinGW wraps Windows sockets in CRT file descriptors in order to mimic the functionality of POSIX sockets. This causes msvcrt.dll to treat sockets as Installable File System (IFS) handles, calling ReadFile, WriteFile, DuplicateHandle and CloseHandle on them. This approach works well in simple cases on recent versions of Windows, but does not support all usage patterns. In particular, using this approach, any attempt to read & write concurrently on the same socket (from one or more processes) will deadlock in a scenario where the read waits for a response from the server which is only invoked after the write. This is what send_pack currently attempts to do in the use_sideband codepath. ---------------------------------------------------------------------------- The new config option "sendpack.sideband" allows to override the side-band-64k capability of the server, and thus makes the dump git protocol work. Other transportation methods like ssh and http/https still benefit from the sideband channel, therefore the default value of "sendpack.sideband" is still true. Signed-off-by: Thomas Braun --- Documentation/config.txt | 6 ++++++ send-pack.c | 14 +++++++++++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/Documentation/config.txt b/Documentation/config.txt index 2cd6bdd7d2..a92c6cd0ba 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -2877,3 +2877,9 @@ web.browser:: Specify a web browser that may be used by some commands. Currently only linkgit:git-instaweb[1] and linkgit:git-help[1] may use it. + +sendpack.sideband:: + Allows to disable the side-band-64k capability for send-pack even + when it is advertised by the server. Makes it possible to work + around a limitation in the git for windows implementation together + with the dump git protocol. Defaults to true. diff --git a/send-pack.c b/send-pack.c index 047bd18fde..bad1b2ba1a 100644 --- a/send-pack.c +++ b/send-pack.c @@ -36,6 +36,16 @@ int option_parse_push_signed(const struct option *opt, die("bad %s argument: %s", opt->long_name, arg); } +static int config_use_sideband = 1; + +static int send_pack_config(const char *var, const char *value, void *unused) +{ + if (!strcmp("sendpack.sideband", var)) + config_use_sideband = git_config_bool(var, value); + + return 0; +} + static int feed_object(const unsigned char *sha1, int fd, int negative) { char buf[42]; @@ -376,6 +386,8 @@ int send_pack(struct send_pack_args *args, struct async demux; const char *push_cert_nonce = NULL; + git_config(send_pack_config, NULL); + /* Does the other end support the reporting? */ if (server_supports("report-status")) status_report = 1; @@ -383,7 +395,7 @@ int send_pack(struct send_pack_args *args, allow_deleting_refs = 1; if (server_supports("ofs-delta")) args->use_ofs_delta = 1; - if (server_supports("side-band-64k")) + if (config_use_sideband && server_supports("side-band-64k")) use_sideband = 1; if (server_supports("quiet")) quiet_supported = 1;